A necropsy that was performed indicated that there would have been no way to stop the spread of the disease, his owners said.

The famous canine was born on November 16, 2009, in Toledo and relocated to Mansfield in 2015.

"He was the most well-mannered dog you could ever meet," said Patricia Duffer.

Duffer said she named him Emperor Rajesh, which translates roughly to Emperor Emperor, because she enjoys names that are unique and of Indian origin.

Weighing just under three pounds and standing just under six inches tall, Rajesh was the smallest known scent-trained cardiac alert dog, according to Duffer.

As an emergency medical response dog, he was specifically trained to be able to smell changes in body chemistry and alert people in the event of cardiac fluctuation, or when he detected symptoms relating to PTSD, with which Duffer is diagnosed.

Duffer also has sick sinus syndrome, which is a heart rhythm disorder. Rajesh was able to smell a change in her normal smell when her heartbeat was too fast or too slow, even before her pacemaker made an adjustment.

When Rajesh barked, she knew that her heart was out of rhythm, and she needed to sit or lay down within a minute or two to avoid fainting.

"Having Raj for me has always been very much a life-saving device," she said.

Rajesh was trained to only make noise if he smelled and detected that Duffer or others around her were in distress. He lived his entire life silent, and the only time he barked was when he knew something was wrong.

Even if he was hungry, he never barked. He once had a can of soup accidentally dropped on his foot in the grocery store, but even then, he didn't make a sound.

It was only after Duffer had an X-ray taken of Rajesh's foot did she discover the break.

Duffer told a story of how Raj jumped into a woman's lap at a wake for a funeral when he could smell she was having a heart issue due to the stress and grief of the situation.

Over his life Rajesh built up a huge following both in person and on social media, and when you see a picture of him, you can see why. With his short legs, apple head, a thick black coat with grey streaks, and a tongue perpetually sticking slightly out of his mouth, it's easy to see why he was loved.

He went everywhere with Duffer.

"You couldn't walk two feet without people asking about him," she said, recalling how people would stop her on the street or in airports.

There were articles and news stories written about him, and Duffer would take Rajesh to fundraisers for various benefits or causes.

"We knew that he drew a crowd and we tried to make that matter," Duffer said.

Duffer and her husband also run a program called Working Dog Chihuahuas.

"I thought it was important to work with training in smaller breeds," Duffer said. "Which is is why I started working with Raj as a Chihuahua. Because a lot of the children and people who need response dogs... if they spend a lot of time in the hospital your golden retriever can't be in your bed with you, and it's a different experience for children especially to have a smaller companion."

In addition to posing for a 2016 calendar that benefited dog charities across the country, Rajesh met several celebrities during his life, including Michael J. Fox, Cedric the Entertainer, Sharon Osbourne, President Bill Clinton and former Ohio State University football player Maurice Clarett, who spoke in Mansfield in October 2015.

Duffer recalled how Clarett at the time said he was scared of dogs because he thought he might be allergic to them, and held Rajesh out at arms-length in a photo op, just in case.

Rajesh is survived by his nearly 3-year-old daughter Princess Sultana Samar, who is following in his paw-prints. She is trained to be an medical alert dog just as her father was. In addition to being a father, Duffer said the late Chihuahua is a grandfather and great-grandfather.

Duffer plans to hold an online auction in April to benefit the Good Samaritan Programs at Phillips Animal Hospital and the Richland County Dog Warden's office. She said the South Carolina-based company PuckerButt Pepper Co. is donating items that can be bid on in addition to a signed script that will be donated by Bill Oakley, who was a longtime writer and producer on "The Simpsons." Donations can also be made to the Duffers via the Facebook page, Rajesh Duffer.

"We're trying to have everything from $25 BP cards on there to things that would maybe bring a slightly bigger amount of money but we don't want to make it where people feel like they have to be able to spend a lot to make a difference," Duffer said.

"I very much feel like I owe it to him to reward what he did for me by trying to do as much good as I can in his memory."